Purification of petroleum and hydrocarbon compounds



I t No Drawing.

' and I am fully aware that it'lias occurred to Patented Feb... 28, i 1933.

TnADpE s .wi cu MEiaI-or nonnqson, ILLINois, ssIenoR To LI COL 01L (murmurs i COMPANY, or nonmson, ILLINOIS, ,4 CORPORATION- or LAWARE I rur'tmion rionori ii'rnonmhnn.nrnnocamaoncomroimns The present invention relates to aprocess of purifying mineral oils andhasparticular reference to a process for removing the sul-' phur and sulphur compounds contained in the oil by treating thesame with cadmium compounds: Of course, I. am awarethatnumerous methods have been proposed for removing the sul-'- phur. and other impurities fromhydrocarbon' oil distillates, such .as gasoline. and kerosene prior' investigators in this field, that those metals which yield. an insoluble sulphide in slightly acid -solution,- ;by ca metathetical re "action; involving asoluble salt of the salcl metal. dissolved intheslightly acid solution anda soluble sulphide would be useful in sweeteninghydrocarb'on oils. Askilled chem-I ist would readily perceive that those metals which are, precipitatedby H S in acid solution in the 'so called sulphide group of the inorganic analytical scheine might, insome form, be suitable forthe purpose of sweet.

ening hydrocarbon oils and indeed many of them have been used I for, such a purpose;-a It has been proposed, therefore, to, use lead,

mercury, cadmium and other heavv-i metals of insoluble sulphide forming characteristics, the most commonly used heavy metal' for -;thispurpose i being undoubtedly lead,

which is usually added to'the oilto'be puri fied in the form of'a. sodium plumbite solu-, tion,ycommonly. referred to as. a lead doctor I solution. r ,n

Now, I have found "that cadmium'zyammonia compounds, that is tosav,"cadmium compounds, whichin solution-yield a com.

plex cadmium" ammon a; ion, give superior results in the sweetening of gasoline and other hydrocarbon oils, to compounds now "in usefor this purpose, since agreater propor-;

I tion-of impurities is removedl I; have found that cadmium sulphideis not suitable in my process because it is insoluble in ammonial I have also found thatth-e precipitate formed by chemical reaction between the impurities and the cadmium ammonia compound "may;

' be recovered by filtering ofl 1 the suspension of the same from, the. treated .oil and then drying and roastingit,..wherebythe oxide is salt formed in situ.

hydrocarbon .oilis. continuously pumped oil impurities, this cadmium compound re -use in thepro'cess.

'moved inv the form of acake. The purified Application mean ye'mber s; 1930., Seria1 1 To, 493,2:49.

obtained. This oxide may be addeddirectly to the unsweetened oil or it maybe dissolvedinnitric acid or other mineral 1 acid, except f sulphuric, and then added to the impure oili, Inother words, thecadmiumbxide and the 55 I ammonia may be addedtothe oil tobe-sweetr' ened, orcadmium nitrate or cadmium nitrate 7 together with ammonia may be addedto the unsweetened oil and the complex ammonia In; carrying my invention into effect I provide; any convenient means wherebythe through ayessel, preferably provided with agitating, means, a-ndinto which is continuously fed through anindependent =inlet-a cadmium ammonia compound. The treated oil is then passedthrough a series of settling. towers where the liquid mass separates into two liquid layers, one of ,which is the ammoniacal cadmium'sol'u'tion and the other of which is the treated oil ,containinggthe cadmium compound resulting from thewre action between, the cadmiumj and the being suspended in the oil.1 The aforesaid ammoniacal cadmium, liquid vwhich has separated from the reaction mass inythe settling towersis pumped from thesettling' towers to a replenishingtankwhere it is enriched in cadmium content to. compensate for the loss sustained during the above describedtreating process; It is then readyfor The -,hydrocarbon oil containing the cadmium compound in suspension is pumped to alfilter press, preferably of theSweetland type, where the cadmium compound is, re-

oil' is pumped to a storage tank. The filter cake is. dried and then oxidizedfin a burner,

preferably of the rotary type, at aftemperaa tulre" of; approximately 1300 F., whereby cadmium oxide-is obtained. The cadmium oxide may'then be treated with an acidin chloride: or. nitrate.- I prefer to use; weak nitric acid and} obtain cadmium nitrate.

9875 diluted form, such as hydrochloric or-nit'ric' acid, to 'yieldthe corresponding-salt,;i. -e.,the

mixed directly with ammonium hydroxide and introduced into the treating vessel in this form. 7

As regards the amount of cadmium compound to be used in proportion to the amount of oil, it is pointedout that it will de end entirely upon the nature of the oil un ergoing treatment. ,I find it advantageous tomake an approximate quantitative analysis of the sulphur and other impurities in the unsweet ened oil by any known method which "is not too timeconsuming. Havingestimated the.

' sulphur content, I'then treat the'oilwitha cadmium solution containing ammonia, 11L which the amount of cadmium present is approximately twice that which is theoretically required to react with the sulphur present.

' The amount of ammonia usedmay vary withto the said'oils a cadmium ammonia com:

pound.

in rather wide-limits, but I find that it is preferable to have an amount present which is in excess of the amount theoretically required toreact with "the cadmiumto form the ammonia cadmium complex ion. I have found that a ten per cent excess gives excellent rev SultSQ o a Either gaseous ammonia, which will of course be issolved by the moisture present,

or ammonia dissolved in water may be usedin the foregoing processes. Ifan ammonia solution is used, I prefer to use-a ten per cent solution. I

Normal temperatures and pressures are preferably used in the foregoingprooesses. Many modifications of the foregoing process will be suggested to one skilled in the art and many changes in detail may be made Without eparting from the spirit of the invention. V V s a As used in the claims, the expression low boilinghydrocarbon oils" kerosene and like oils. h

iWhat I claim is: 1

7 means gasoline,

inghydrocarbonoils which comprises adding "-2. The process of desulphurizing low boiling hydrocarbon oils which comprises adding to the said oils a cadmium ammonia compound solution containing excess ammonia.

3. The process of desulphurizing low boiling hydrocarbon oils which comprises adding to the said oils avcadmium ammonia com-r pound while stirring the said oils.

4. The process'of desulphurizing low boiling'hydrocarbonoils which comprises adding o to the said oils a-cadmium ammonia-com,

pound solution containing excess ammonia while stirring the said oils.-

j5. Theprocess of desulphurizing low boil- I ing hydrocarbon oilswhich comprises adding to the said oils cadmium oxide'andammonia,

6.'The process of desulphurizinglow boiling hydrocarbon oils whichcomprlses dd p -while stirring thereaction said oils.

1. The process of desulphurizing low'boilto the said oils cadmium oxide and ammonia and stirring the reaction said oils.

7. The process of desulphurizing low boil- 1 ing hydrocarbon oils which comprises adding ing; the said. oils with cadmium ammonia nitrate.

. 11. The processof desulphurizing low boilinglhydrocarbon oils which comprisestreating the said oils with cadmium ammonia nitrate in excess ammonia while stirring the said oils. 7 7

12. The process of desulphurizing low boiling hydrocarbon-oils which comprisescontinuously feeding the impure oil to a treating vessel, continuousl adding a cadmium compound andammonia, conducting the resulting mass to settling towers, removing the treated oil, filtering the sameto recover the cadmium compound, drying and oxidizing the residue from the filtration, recovering the resulting cadmium oxide and returning the same to the process. a

' 13. The process of desulphurizing low boiling hydrocarbon oils which comprises'adding to the saidfoilscadmium chloride and ammonia. a a

j 14.The process of desulphurizing low boil- Ling hydrocarbonoils which comprises adding to the said oils cadmium chloride and amnwniawhilestirring the reaction said oils.

I 15. The process of desulphurizing low boiling hydrocarbon oils which comprises adding to the said oil's cadmium chloride and excess ammonia. a a

16. The process of desulphurizing low boiling h drocarbon oils which comprises treating t o said oils with cadmium ammonia chlorideii r 17. The process'of desulphurizinglow boiling hydrocarbon oils which comprises treating the said oils with cadmium ammonia chloride'inexoess ammonia while stirring the fSfildOllS.

1 In testimony whereof I aflixmy signature. v 'THADDEUS' 'CULMER. 

